Process of purifying potassium bitartrate.



MAN UEL FE [th' A N D lii MARTINEZ, O1 JEREZ D ll LA FRONIERA, SPAIN.

PROCESS-OF PURIFYING E'OTASSIUMBITARTRATE.

Specification of Letters Patent,

Patented April 20, 1909.

,Application filed December 30, 1907. Serial No. 408,667.

To all-whom it may concern:

.Be It known that I, MANUEL FERNANDEZ MARTINEZ, a sub ect of the King ofSpain,

"residing at Jercz 'de la Frontera, Spain, have invented certain new andusefullmprovev- I merits in Processes for the Extraction W 1thout Use ofFuel of Bitartrate of Potash, of which the following is a specification.

My invention relates to a'process for the extraction or recovery olbitartrate of potash inn ure or. nearly pure form, from wine lees,

resir ua l dregs, or the crude tartar which is deposited during thel'ern ientation of grape price.

The invention has for its object the reali zation of such a processwithout the consu n ption of fuel.

The various methods now commonly in use "for the extraction of potassiumbitartrate involve the application of a great deal of heat at variousstages of the several proccsses.

To the end of reducing the great expense of such operations resultingfrom such application of heat, I have devised a process the severalsteps of which involve the application in the cold of the variouschemicals used, and by which I am enabled to l'urther reduce the expenseby the use of wooden receptacles.

To more clearly set forth the exact nature of my improved process, I mixthe argol or crude tartar obtained from the fermentation of grape juice,and which has been cleaned by any suitable meansto remove extraneousdirt such as portions of "rape stalks, etc, with either nitric, hydrochoric, hydrofluoric, or sulfuric. acids, diluted with water and appliedin the cold state; the tartar may, or may not, be applied in thepulverized state. The materials having been mixed as above, agitation isresorted to until the solid substances composing the crude tartararethoroughly dissolved. The solution thus obtained is then filtered bvmeans of a filter press. I then treat the filtered liquid withanu'itable variety of clay, or with charcoal, which act as absorbents ofthe organic coloring matters contained which were originally derivedfrom the grape 'uice or wine; I continue this operation until the liquidis decolorized. The next step in the )rocess consistsin the separation"from the li uid so treated, of the various metallic stilts which areusually associated with bitartrate of potassium in crude tartar; suchcompounds.

salts usually consist of certain iron, copper, lead, magnesium andaluminium compounds wl'iich are derived from various sources during theformation of the dregs or tartar or froni in pui-ities in thechei'cicals used in the process.

The soluti'oirwill usually contain a mixture ol; salts of the abovenamed metals, and may also contain arsenic'and amnonium I preferablyneutralize such a solution by means of potash or the salts of thissubstance, or by nxeans of soda and its salts, after which the metallicsalts present are precipitated bythe addition to the liguld of eithersodium sulfid, potassium sulfi v or ammonium sulfid. When the metallicimpurities present are confined to iron and copper compounds only,

I may treat the original solution withthcproper quantity of ferricyanidof potassium, which will produce a precipitate of ferricyanid of copperand of ferric ferricyanid.

When the original solution contains iron as the only metallic im' urity,I add thereto the proper quantity 0 suliocyanid of potassium, which,reacting with the iron salts present, will produce 'sulfocyanid of ironwith its attendant red coloration. I may then introduce into thesolution either aniyl alcohol or ether, agitate thoroughly the mixtureand allow to settle, when it will be found that the mixture hasseparated intotwo layers, of I which the one consisting of the amylalcohol or other contains the sulfocyanid of iron, and the'oneconsisting of the original acid solution will be found to be clear andfree. from any red coloration of the said sulfocyanid. The .amyl alcoholor ether used may be recovered and purified by distillatio v Thesolutions obtained by the hereinbefore described method of treatmentwhere several metals are involved, or in either of the special methodsof treatment described are now subjected to filtration, by whichmeans'the precipitate is separated. To the acid solution thus treatedand which isnow free from metals, I add potash or any of its salts untilno more'bitartrate of otassium is precipitated. The clear liquit 'isdecanted; I then subject the bitartrate of potassium to the action of acentrifugal machine, and finally dry it by any suitable means.

The mother liquid which is obtained by the above process will contain aconsiderable quantity oleither rhlorid, nitrate, fluorid or sulfate ofpotassium, according to the resprrtive arid employed in the 'earlystages of the process. l lind no disadvantage to the working ol myprocess by using this mother liquor several successive times; it willthen be saturated with one of the above conipounds to the extent that itis economical to recover the salt.

All the steps oi the above described process may be carried outwith theuse of wooden vessels, and the chemical "operations deseribed arr-:usroniplished without the consumption ol fuel. I

llaviug thus described my invention what 1 claim is 1. Thehereiiulescribed prooess for the e):- tractien ol' l'iitartrate ofpotassium, which consists in treating, erude tartar with a mineral acidin the cold state, filtering and decolorizing the resulting liquid,treating said liquid with an alkaline salt, precipitating the .uietalliocompounds in the solution, filtering the solution, then adding a potash.salt to the 5 filtered solution to precipitate bitartrate of potassium,substantially as set forth.

trate of potassium, which consists in dissolving crude tartar in amineral acid in the cold state, filtering the resulting liquid anddeeolorizing it by means of clay, treating the liquid so obtained with apotash salt, preci itating foreign metallic substances by an al alinesulfid, separating the said metallic precipitate by filtration, adding apotash salt eipitate of bitartrate of potassium is obtained, thensubjecting the said bitartrate to the action of a centrifugal machine,and dr ing it, all the o )erations describedbeing eifeeted, HltllOLllJ te consumption of fuel, substantially as described.

In testimony whereof I aflix my signature in presence of two Witnesses.

MANUEL FERNANDEZ MARTINEZ. Witnesses ToMAs DE LA (JUEsTA, FRANCISCO(:iARCIA.

2. A process for the extraction of bitar to the filtered liquid wherebya pure pre-'

